The final REFRESH newsletter is now available on the REFRESH file store at http://www.refresh.ucl.ac.uk/webfm_send/2405. This focuses on the WP5 and WP6 work done at the REFRESH demonstration catchments.
The EU Water Framework Directive environmental objectives are established on the basis of ecological status assessment, focused on five species groups (macroinvertebrates, fish, phytoplankton, macrophytes and phytobenthos). The assessments do not considering zooplankton. REFRESH has demonstrated that zooplankton is an important, integrative and cost-efficient indicator of the ecological quality of lakes and of recovery after restoration. We recommend that zooplankton metrics be included among mandatory biological quality elements for lakes as this will improve our capacity for lake management under future climate and land use changes.
Stream water temperature is predicted to increase with climate change, and will affect stream biotic assemblages and ecosystem functioning, threatening the implementation of the EU Water Framework Directive and Biodiversity Strategy 2020. Results from the REFRESH project conducted in five lowland temperate streams show that the presence of riparian forest has a cooling effect ranging from 1°C to 3°C, depending on the reach length and canopy cover. River restoration by planting riparian trees, combined with open reaches allowing the presence of aquatic plants, can be a useful adaptation measure to combat the negative effects of future warmer temperatures on freshwater life.
Despite improvements in some regions, nutrient loading from agriculture remains a major pressure on Europe's freshwaters, resulting in widespread eutrophication. The main consequences of nutrient enrichment include excess phytoplankton growth, increased frequency of cyanobacteria blooms, and depletion of dissolved oxygen, all leading to a decline in water quality and biodiversity. REFRESH provides new evidence for climate change impacts on lakes, showing that increased lake temperatures generally have a eutrophication-like effect.
As the impact of eutrophication and climate change follow the same pathways affecting nutrient availability and cascading effects in the food web, and given the high variability of both pressures, it is unlikely that their impacts can be disentangled in each particular case.
A review of more than 450 climate change adaptation measures related to water carried out by the REFRESH concludes that all measures leading to reduced nutrient losses from agriculture can be considered win-win measures as they meet environmental objectives set by the Water Framework Directive and will enhance the resilience of lake ecosystems under future climate change.